<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<form>
    用户名:<input type="text" name="username" @blur="check()" placeholder="用户名">{{info}}<br>
    密码:<input type="text" name="password" placeholder="密码"><br>
    昵称:<input type="text" name="nick" placeholder="昵称"><br>
    <input type="button" value="注册" @click="reg()">
</form>
<!--引入axios和vue-->
<script src="https://cdn.bootcdn.net/ajax/libs/axios/0.21.1/axios.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.6.14/vue.js"></script>
<script>
    let v = new Vue({
        el:"form",
        data:{
            info:""
        },
        methods:{
            check(){
               let dataForm =  new FormData(document.querySelector("form"));
               axios.post("/check",dataForm).then(function (response) {
                   if(response.data==1){
                       v.info="用户名可用";
                   }else{
                       v.info="用户名不可用"
                   }
               })
            },
            reg(){
                let dataForm =  new FormData(document.querySelector("form"));
                axios.post("/reg",dataForm).then(function (response) {
                    if(response.data==1){
                        alert("注册成功");
                    }else {
                        alert("用户名被占用");
                    }
                })
            }
        }
    })
</script>

</body>
</html>